David Nussbaum, head of WWF UK, said “sustained pressure” was required from political leaders to combat climate change. He said it was only when “real indicators” of climate change came, such as floods and droughts, that public perceptions changed.

He told The Independent: “Of course people’s concerns about climate change changed in 2009 when economic pressures were rising… [But] the problems haven’t gone away… There are longer-term concerns that may not seem imminent that are extremely serious. A skilled political leader has got to grapple with how you act and respond to the immediate pressure people feel while helping [to take] account of the wider concerns and interests.”

Campaigners said the “perceived seriousness” of climate change had also fallen sharply since the unsuccessful UN Climate Change Summit in Copenhagen in December 2009. The summit ended in what was described as “confusion, disagreement and disarray” as political leaders failed to agree a legally binding deal to curb greenhouse gas emissions.

Graham Thompson, a spokesman for Greenpeace, said: “The public can see that the response of our politicians is completely inadequate to the threat scientists have revealed, and that dissonance is reflected in these polls.”

Doug Miller, chairman of GlobeScan, said: “Evidence of environmental damage is stronger than ever, but our data shows that economic crisis and a lack of political leadership mean that the public are starting to tune out.”

The Department of Energy and Climate Change reiterated the view of Ed Davey, Climate Change Secretary, that “the basic physics of climate change is irrefutable”.

If you look at the last decade of global temperature, it’s not increasing,” Barnes said. “There’s a lot of scatter to it. But the [climate] models go up. And that has to be explained. Why didn’t we warm up?”

The question itself, while simple sounding, is loaded. By any measure, the decade from 2000 to 2010 was the warmest in modern history. However, 1998 remains the single warmest year on record, though by some accounts last year tied its heat. Temperatures following 1998 stayed relatively flat for 10 years, with the heat in 2008 about equaling temperatures at the decade’s start. The warming, as scientists say, went on “hiatus.”

The hiatus was not unexpected. Variability in the climate can suppress rising temperatures temporarily, though before this decade scientists were uncertain how long such pauses could last. In any case, one decade is not long enough to say anything about human effects on climate; as one forthcoming paper lays out, 17 years is required.

(…)

….for others, this simple answer was a failure. If scientists were going to attribute the stall to natural variability, they faced a burden to explain, in a precise way, how this variation worked. Without evidence, their statements were no better than the unsubstantiated theories circulated by climate skeptics on the Internet.

“It has always bothered me,” said Kevin Trenberth, head of the climate analysis section at the National Center for Atmospheric Research. “Natural variability is not a cause. One has to say what aspect of natural variability.”

(…)

“What’s really been exciting to me about this last 10-year period is that it has made people think about decadal variability much more carefully than they probably have before,” said Susan Solomon, an atmospheric chemist and former lead author of the United Nations’ climate change report, during a recent visit to MIT. “And that’s all good. There is no silver bullet. In this case, it’s four pieces or five pieces of silver buckshot.” [fortsætter Trenberth]

(…)

Indeed, the most important outcome from the energy hunt may be that researchers are chronically underestimating air pollution’s reflective effect, said NASA’s James Hansen, head of the Goddard Institute for Space Studies.

Recent data has forced him to revise his views on how much of the sun’s energy is stored in the oceans, committing the planet to warming. Instead, he says, air pollution from fossil fuel burning, directly and indirectly, has been masking greenhouse warming more than anyone knew.

It is a “Faustian bargain,” he said, and a deal that will come due sooner than assumed.

(…)

Researchers have long argued that using 1998 as a starting point was, then, unfair.

“Climate scientists were right that it was a cherry-picked observation, starting with an El Niño and ending with a La Niña,” said Robert Kaufmann, a geographer at Boston University who recently studied the hiatus period.

The temperature spike of 1998 was not just about El Niño, though; it was also enabled by an absence in the air. From the 1950s to the late 1970s, it is now widely agreed that the smog and particles from fossil fuel burning, by reflecting some of the sun’s light back into space, masked any heating that would be felt from increased greenhouse gases. As clean air laws began to pass in the United States and Europe, this pollution began to disappear in the 1990s, a process known as “global brightening.”

(…)

“We make a mistake, anytime the temperature goes up, you imply this is due to global warming,” he said. “If you make a big deal about every time it goes up, it seems like you should make a big deal about every time it goes down.”

For a decade, that’s exactly what happened. Skeptics made exaggerated claims about “global cooling,” pointing to 1998. (For one representative example, two years ago columnist George Will referred to 1998 as warming’s “apogee.”) Scientists had to play defense, said Ben Santer, a climate modeler at Lawrence Livermore National Laboratory.

“This no-warming-since-1998 discussion has prompted people to think about the why and try to understand the why,” Santer said. “But it’s also prompted people to correct these incorrect claims.”

Even without skeptics, though, the work explaining the hiatus, and especially refining the planet’s energy imbalance, would have happened, NASA’s Hansen added.

It was in no “way affected by the nonsensical statements of contrarians,” Hansen said. “These are fundamental matters that the science has always been focused on. The problem has been the absence of [scientific] observations.”

(…)

Indeed, many of the scientists sorting out the warming hiatus disagree with one another — in a chummy, scholarly way. Judith Lean, the solar scientist, finds Kaufmann’s work unpersuasive and unnecessarily critical of China. Kaufmann finds Solomon’s stratosphere studies lacking in evidence. Hansen and Trenberth can’t agree on a budget.

It seems staggering, then, that in a few years’ time a new consensus will form for the next U.N. climate change report. But it will, and lurking beneath it will remain, as always, the churning theories and rivalries, the questions, the grist of scientific life.

So, in the end, can anyone say explicitly what caused the warming hiatus?

As the scientific community, we were just not prepared for the temperature not rising for a decade as CO2 concentrations rose. We had not thought enough about the possibility of falsification. [...] We concentrated too much on looking ahead and said: Great! Everything fits our explanation. For many colleagues asking questions was frowned upon because this ‘could provide the climate skeptics with ammo‘. And that is a methodical failure.”

Don’t look now, but maybe a scientific consensus exists concerning global warming after all. Only 36 percent of geoscientists and engineers believe that humans are creating a global warming crisis, according to a survey reported in the peer-reviewed Organization Studies. By contrast, a strong majority of the 1,077 respondents believe that nature is the primary cause of recent global warming and/or that future global warming will not be a very serious problem.

The survey results show geoscientists (also known as earth scientists) and engineers hold similar views as meteorologists. Two recent surveys of meteorologists (summarized here and here) revealed similar skepticism of alarmist global warming claims.

According to the newly published survey of geoscientists and engineers, merely 36 percent of respondents fit the “Comply with Kyoto” model. The scientists in this group “express the strong belief that climate change is happening, that it is not a normal cycle of nature, and humans are the main or central cause.”

The authors of the survey report, however, note that the overwhelming majority of scientists fall within four other models, each of which is skeptical of alarmist global warming claims.